Means for simultaneously operating the valves in internal combustion engines



Dec. 15', 1931. G, FORNACA .1,836,111

MEANS FOR SIMULTANEOUSLY OPERATING THE VALVES IN INTERNAL COMBUSTION ENGINES Filed March 20, 1926 2 Sheets-Sheet l .lv Im 6 DCC. 15, 1931. Q FORNACA MEANS FOR SIMULTANEOUSLY OPERATING THE VALVES IN INTERNAL COMBUSTION ENGINES Filed March 2O Patented Dec. l5, 1931 UNITED STATES PATENT OFFICE GUIDO FORNACA, OF TURIN, ITALY; LUIGI FORNACA, EXECUTOR F SAID GUIDO FORNACA, DECEASED, ASSIGNOR TO FIAT SOCIETA ANONIMA, OF TURIN, ITALY MEANS FOR SIMULTANEOUSLY OPERATING THE VALVES IN COMBUSTION ENGINES INTERNAL Application led. March 20, 1926, Serial No. 96,228, and in Italy March 23, 1925.

`This invention provides improved mechanism for simultaneously operating two (or more) valves 1n an internal combustion engme, characterized 1n that sald valves are equipped with across piece guided by a central stem andactuated by cams acting symmetrically with respect to the guiding axis, 4so that no bending stress will be generated on" the valve and guiding stem.

' Preferably, said guiding stem engages, at one of its ends, in a socket in the cylinder head while its other end is connected with the camshaft by means of ayoke formed in two parts and easily removable. l

Under this arrangement the guiding member is practically independent of the cylinin the plane C-D of der head but is, on the contrary, dependent on the position of the camshaft; whereby a simpler construction and a greater precision are attained.

As the cams work always in pairs (or sets) and in a perfectly symmetrical way with regard to the guide axes, abnormal stresses of the guides are avoided and wear is minimized while all inconveniences due to the formation of play between the rubbing parts are vdone away with.

The annexed drawings shown diagram-l matically and by way of example a constructional form of the improved Valve mechanism.

Fig. 1 is a vertical section in the plane A-B of Fig. 2. 1. s

Fig. 2 isa side View,Fpartially in section,

With reference to the drawings, 1 denotes the engine head, each engine cylinder being provided with four valves, namely two suction'and two exhaust valves. The suction valves 2 and 2 and the exhaust valves are operated from two separate camshafts 3, and the cams 4 on each camshaftwork in pairs on cross pieces 5 arranged above the valves, one for each pair. Each cross piece has two tap- 7 pets 6 and a guide 7, the latter being slidable on a stem 8 held, at its lower part, in a socketv9 in the head 1 and, at its upper parts, by a two ing cams 4, 4.-.

part yoke 10, 11 loosely mounted on the camshaft 3 between thefcorrespond-l The valves are normally held againsttheir seats 15 by means of double springs 16.

Under the action of the cams .4, each cross plece 5 is ly disposed with respect to the axi'sC*-D of the guidev stem and will therefore be depressed to openv the valves without producing any stress tending to bringA it in'an inclined e the guide.

What I claim is:

In a valve bustion engines, der head having pair of valves in said head, a crosspiececonnected to the stems of the valves, a camshaft above the cross piecein the plane passing through the axes of the valve stems, two cams on the shaft engaging the crosspiece, and a guide for the latter loosely hung ink proxlmity to pressed at two points symmetricalf piece may mechanism fork internal comthe combination of a cylina socket formed therein, a` v on the shaft between the two cams and .havf ing its free end extending into and guided by the socket on the cylinder head.

'v In testimony that I claim thev foregoing as my invention I have signed my name.

GUIDO roinvaoa.V 

